Electrification of sand on Titan and its influence on sediment transport

Autor: George D. McDonald, Devon M. Burr, Michael Malaska, J. S. Méndez Harper, Josef Dufek, J. McAdams, James J. Wray, Alexander G. Hayes
Rok vydání: 2017
Předmět:
Zdroj: Nature Geoscience. 10:260-265
ISSN: 1752-0908
1752-0894
DOI: 10.1038/ngeo2921
Popis: Triboelectric, or frictional, charging is a ubiquitous yet poorly understood phenomenon in granular flows. Recognized in terrestrial volcanic plumes and sand storms, such electrification mechanisms are possibly present on Titan. There, dunes and plains of low-density organic particles blanket extensive regions of the surface. Unlike Earth, Titan hosts granular reservoirs whose physical and chemical properties possibly enhance the effects of charging on particle motion. Here we demonstrate in laboratory tumbler experiments under atmospheric conditions and using organic materials analogous to Titan that Titan sands can readily charge triboelectrically. We suggest that the resulting electrostatic forces are strong enough to promote aggregation of granular materials and affect sediment transport on Titan. Indeed, our experiments show that electrostatic forces may increase the saltation threshold for grains by up to an order of magnitude. Efficient electrification may explain puzzling observations on Titan such as the mismatch between dune orientations and inferred wind fields. We conclude that, unlike other Solar System bodies, nanometre-scale electrostatic processes may shape the geomorphological features of Titan across the moon’s surface. Frictional charging of granular materials may readily occur on Saturn’s moon Titan. Laboratory experiments under Titan-like conditions suggest that the resulting electrostatic forces are strong enough to affect sand transport on Titan.
Databáze: OpenAIRE
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